Time delay relay



March 22, 1938. G. c. ARMSTRONG TIME DELAY RELAY Filed Oct. 23, 1955INVENTOR Geozye 6T flr/rzszrargg BY /Z/U7 ATTORNEY Patented Mar. 22,1938 UNITED STATES PATENT OFFICE TIMIE DELAY RELAY George G. Armstrong,

Forest Hills, Pa, assignof Pennsylvania Application October 23, i935,Serial No. 46,283

5 Claims.

This invention relates to delayed-action relays and more particularly torelays of this type in which the delay is controlled by means of adevice actuated by a branch magnetic circuit.

It is an object of this invention to apply the method of producingrotation described in my copending application Serial No. 46,287, filedOctober 23, 1935, and to use this method for controlling the delay in adelayed-action relay.

Other objects of my invention and. details of the proposed constructionwill be evident from the following description and the accompanyingdrawing, in which:

Figure 1 shows one form of my device;

Fig. 2 shows a modification thereof;

Fig. 3 illustrates a further modification; and

Fig. 4'the preferred form.

A magnetic circuit l is provided comprising a magnet proper 2 and itsarmature 3. The magnet proper is energized by alternating current in acoil 4. A shading coil 5 at the pole 6 is provided for insuring anuninterrupted pull from the alternating-current flux. Contacts arecontrolled by the movement of the armature in the usual way. A rotor I0is mounted so as to have rolling contact with the end surface II of thearmature A non-magnetic stirrup I2 provides bearings for a shaft throughthe rotor. This shaft preferably is not directly connected to the rotorit, but a spiral spring unites them, providing for some angular movementof the rotor H] with reference to its shaft. When the rotor rotates, itsmotion is transmitted to the shaft, any irregularity in the rotationbeing more or less absorbed thereby.

A spring [5 mounted from the same stirrup l2 biases the rotor l0 awayfrom the adjacent pole of the magnet 2. A pinion, not shown, on the endof the shaft meshes with a sector I6, engagement between the pinion andthe sector preventing movement of the armature 3 toward the magnet 2. Aspring I1, mounted from the magnet by any convenient support I8, acts toreturn the sector to its original position when released.

In the operation of this form of the device, when the coil 4 isenergized with alternating current, a flux is set up between the poleface 6 and the end of the armature 3. This draws the pinion into meshwith the sector l6 if in the deenergized position they are out ofengagement.

The rotor I0 is in the path of a leakage flux which extends from poleface 6 through a part of the rotor and enters the armature 3 at the faceH. The action of the flux where it enters the face H and the spring 15,as explained in my above-mentioned copending application, tends to setup a rotation of the rotor l0, partly on account of its own hysteresis.

The rotation is counter-clockwise as shown in Fig. 1. It thereforedrives the sector l6 down- Ward, stretching the spring ll until theupper end of the segmental gear I16 passes below the pinion. The fluxbetween members 6 and 3 then causes the armature to move and the pinionto ride upon the upper edge of the sector I6.

When the current ceases in the coil 4, the armature 3 is returned to theillustrated position, either by gravity or by a spring which is notshown. When, during its return movement, the pinion passes off of theupper edge of the sector it, the spring ill will lift the sector to theillustrated position. The pinion may then engage the teeth of the sectorit or if the motion of the armature 3 is great enough it may be too farto the right to engage them.

In the form of the device illustrated in Fig. 2,

the magnet 2 has mounted thereon an iron bail,

formir a branch magnetic circuit 20. The mounting includes a piece ofnon-magnetic material 2i, whereby flux which goes through member 23 issmall in amount as compared with the flux in the main magnetic circuit.The rotor I0 is mounted to bear against the surface of the end i of thebail-shaped iron 20. The mounting is by means of a non-magnetic stirrup22 and includes a spring 23 biasing the rotor l0 away from the pole 6 ofthe magnet 2. A pinion 24 mounted on the end of the shaft of the rotormeshes with a sector 25 mounted on the free end of the armature 3.

In the operation of this form of the device, when the coil 4 isenergized with alternating current, the armature 3 is attracted towardthe magnet 2 and the sector 25 comes into mesh with the pinion 24, if itwere not already in mesh. The rotor i0 is subjected to flux between thebailshaped iron 23 and the pole 6. Between member 20 and'the rotor thisflux passes nearly at right angles to the surface 2'! and again betweenthe rotor 10 and the pole 6 the flux emerges nearly at right angles tothe surface.

At times in the cycle of this flux, the portion of the rotor l0 adjacentthe bail 20 will be of opposite polarity to that of the contiguous partof the bail 20, but at times, because of the hysteresis of the rotor i0,these two polarities will be alike. The flux between the pole 6 and therotor ID attracts the rotor iil against the action of the spring 23 andwhen this flux diminishes or becomes zero the spring 23 returns therotor I0 upward.

The combineffect of these actions will cause the rotor i0 rotate in a d'ection clockwise as seen in Fig. moves the actor 25 downward againstthe action of the spring 26 until the end of the sector disengagespinion 24. The between members 6 and 3 n moves the armature 3 toward theleft as shown in 2 and the pinion 24 will ride upon the upper edge ofthe sector.

When the current in coil 4 is cut off, the armature 3 is retiuned to theillustrated position, by gravity or by the action of a spring, notshown. This will cause the sector 25 to move upward under the action ofthe spring 26, into a position in which it will engage the pinion 24 orwill be ready to do so upon energization of the coil 4.

The non-magnetic piece 2| was introduced in order to insure that theiiux through the bailshaped piece 20 will be small, the flux from pole 6to armature 3 will thus be but slightly diminished by the action of themagnetic shunt.

In the form shown in Fig. 3, the rotor l0 has been shown upon the otherface of the bailshaped member 20, other parts being as described inconnection with Fig. 2. When the coil 4 is energized with alternatingcurrent, the rotor l0 causes a pinion (similar to pinion 24 in Fig. 2)to turn counter-clockwise as seen in Fig. 3 and the sector 25 movesupward until it escapes the pinion. The flux between pole 6 and armature3 then moves armature 3 toward the left as shown in Fig. 3, and thelower edge of sector 25 slides over the pinion. When the current in thecoil 4 ceases the armature 3 is returned to its original position andthe sector 25 is dragged off of the pinion so that it is in engagementwith the teeth thereof or is ready to become engaged as soon as the coilis re-energized.

In the form illustrated in Fig. 4, the piece 30 mounted on the magnet 2adjacent to the pole 6 is of iron, but the bracket 3| in which the shaftfor the rotor I0 is mounted is of non-magnetic material. A spring 32 ismounted in a position to press the rotor l0 away from the iron piece 30.The sector 33 is provided with a notch which can receive the pinion uponthe shaft of the rotor I0 when the sector has been rotated far enoughfor that purpose. The mounting 34 which carries the sector 33 is ofnon-magnetic material.

In the operation of the device when the coil 4 is energized byalternating current, the rotor I0 is subject to a flux which is obliqueto the surface of the bracket 3| with which the rotor contacts. When therotor I0 is moving under the attraction of the piece 30, it is actedupon by the spring 32. Because of the hysteresis of the rotor lo, theportion of it in contact with the bracket 3| is sometimes of the samepolarity as the iron piece 30 and sometimes of opposite polarity.

When the motion has become steady, the time wherein these polarities arealike is a greater fraction of the time when the rotor is moving underthe action of the spring 32 than is the time when they are unlike, andthe time when they are unlike during the motion of the rotor ||I againstthe action of spring 32 is greater than the time during this motion thatthey are alike. The result of this is a rotation of the rotor l0counter-clockwise as seen in Fig. 4. While the coil 4 is energized withalternating current, the armature 3 is attracted, pulling the sector 33into engagement with the pinion unless it was already in engagement andthe rotor I0 turns counter-clockwise as just explained. Turningcounter-clockwise, it brings one edge of the notch in sector 33 abovethe pinion. The attraction between members 6 and 3 then moves thearmature to the left and that edge of the notch slides over the pinion.When the coil is deenergized the armature returns to its original posltion and the notch returns to the illustrated position under the actionof spring.

Other variations of this invention will occur to those skilled in theart, and I do not wish to be limited to only the forms specificallyillustrated and described.

I claim as my invention:

1. In a delayed-action relay, 9. main magnetic circuit including anarmature, a rotary device including a rotor, a bearing surface on whichsaid rotor rests, means constituting a branch magnetic circuit forproducing flux through said rotor oblique to said surface, and a springbiasing said rotor away from the position toward which it is attractedby said flux, an obstacle preventing complete response to the flux bysaid armature and gearing operated by said rotor and acting to move saidobstacle to an inoperative position.

2. In a delayed-action relay, a magnetic structure including acontact-operating armature, delay mechanism comprising an obstaclenormally preventing completion of the movement of said armature, amechanism including a magnetic rotor for moving said obstacle to anonobstructing position, said rotor rolling on a surface of saidmagnetic structure whereby fiux passes between said rotor and saidsurface at the line of rolling contact, and a magnetic shunt distinctfrom said magnetic structure producing flux for operating said rotor.

3. In a relay, a main magnetic structure, a branch magnetic structure,an armature in said main magnetic structure, an obstacle to the closingof said armature and means, including a rotary device responsive to theflux in said branch magnetic structure for moving said obstacle to aninoperative position, said rotary device rolling on a surface of one ofsaid magnetic structures whereby flux passes between said rotor and saidsurface at the line of rolling contact.

4. In a relay, 9. main magnetic structure, a branch magnetic structure,an armature in said main magnetic structure, an obstacle to the closingof said armature and means, including a. spring and a magnetic rotorresponsive to both the flux in said branch magnetic structure and tosaid spring to produce rotary motion thereof, said rotor rolling on asurface of one of said magnetic structures whereby flux passes betweensaid rotor and said surface at the line of roll ing contact, and amechanism actuated by said rotary motion to move the obstacle to anonobstructing position.

5. In a relay, a main magnetic structure including an armature, amagnetic rotor, means constituting a branch magnetic structure forproducing an attracting flux through said rotor, said rotor rolling on asurface of one of said magnetic structures whereby flux passes betweensaid rotor and said surface at the line of rolling contact, spring meansbiasing said rolling rotor away from the position toward which it isattracted by said flux, an obstacle preventing complete response totheflux by said armature, and means operated by said rotor to move saidobstacle to an inoperative position.

GEORGE C. ARMSTRONG.

